Apparatus for piercing and clenching superposed sheets



Feb. 19, 1952 J. PETTOROSSI APPARATUS FOR PIERCING AND CLENCHING SUPERPOSED SHEETS 2 SHEETSSHEET 1 Filed June 11, 1948 a 1 m I. m M m up n F .m

. INVENTOR. Joseph Pet torossi /AT;0RNEY5 J. PETTQROSSL 2,586,479-

Feb. 19, 1952 APPARATUS FOR PIERCING AND CLENCHING SUPERPOSED SHEETS Filed June 11, 1948 2 SHEETS-SHEET 2 ATTORNEYS Patented Feb. 19, 1952 APPARATUS FOR PIERCING AND CLENCH- ING SUPERPOSED SHEETS Joseph Pettorossi, Brooklyn, N. Y., assignor to Paper Novelty Manufacturing Company, a corporation of New York Application June 11, 1948, Serial No. 32,301

3 Claims. 1

The invention relates to apparatus for clenching together a plurality of superposed sheets of material. Particularly the invention relates to an attachment for a presshaving a, reciprocating hammer and a stationary bed, said attachment adapting the press to operate as a clenching machine.

The general object of the invention is to provide a novel and a simple apparatus for transfixing and thereby rupturing, as by spearing, a plurality of superimposed sheets so as to force burrs resulting from the rupture of the material of the surrounding, the transfixing or spearing implement, as it passes through the uppermost sheets, through the correspondingly formed aperture'of the lowermost sheet, and for flattening such burrs against the underside of the lowermost sheet around the rupture thereof, for the purpose of clenching the several sheets together in a manner similar to the binding together of the several sheets by a hollow rivet, but with the additional binding and securing action of the burrs.

A special object of the invention is to provide apparatus of the class described which is adapted for clenching together a plurality of superposed sheets of material at a plurality of stations surrounding registered perforations in the several sheets, so that, for example, the several sheets may be secured each to the other near such registered perforations, but not elsewhere, whereby the peripheral portions of the sheets may be bent variously in accordance with a desired design without disassembling the component sheets.

More particularly, the invention contemplates apparatus for clenching together, in the manner described above, a plurality of die cut and formed sheets of material, each being centrally perforate, for the purpose of making a, Christmas tree ornament, such as a rosette or star for use as a frame or reflector for an electric light bulb or candle holder.

The invention is useful in applications not restricted to the punching and clenching together of several sheets around a centrally disposed aperture, as will be fully understood from the following description and from the drawings; but is particularly well suited for punching and clenching operations where it is desired that a plurality of such operations take place at one time.

The drawing illustrates an exemplary embodiment of the invention, which comprises two cooperating die assemblies adapted to transfix and rupture, as by spearing, a plurality of superposed sheets of material at five equally spaced stations surrounding registered like perforations in the several sheets and thereby forcing burrs, resulting from the rupturing of the upper sheets. through the ruptures of a lower sheet, and for clenching said burrs against the underside of said lower sheet for the purpose of-riveting the several sheets together.

In the drawings:

Fig. 1 is an elevational view of the two die assemblies in normal or inoperative position;

Fig. 2 is a top plan view of the lower die assembly;

Fig. 3 is a bottom plan view of the lower die assembly;

Figs. 4, 5, 6 and 7 are illustrative of the work performed by the die assemblies, and are more particularly described in the following description;

Fig. 8 is an enlarged, fragmentary axial section of portions of the two die assemblies in one operative position, the plane of the section being indicated by the line 8-8 of Fig. 2;

Fig. 9 is the section 9-9 of Fig. 3, showing the two die assemblies in normal or inoperative position;

Fig. 10 is a section on the plane of that of Fig. 9, showing all of the upper die assembly, and the upper part of the lower die assembly, each in the operative position illustrated in Fig. 8;

Fig. 11 is a bottom plan view of the upper die assembly;

Fig. 12 is an elevational view of the punch of the upper die assembly separated from other parts of the assembly; and

Fig. 13 is an enlarged, fragmentary, axial section of portions of the two die assemblies in an operative position subsequent to that illustrated in Fig. 8, the plane of the section being indicated by the line 8-8 of Fig. 2.

An embodiment of the invention, adopted for the purpose of illustration herein, comprises a pair of cooperating die assemblies suitable for fixing together a plurality of relatively thin sheets by punching and clenching the same at five spaced stations surrounding registered perforations in the several sheets. The operation for which the illustrated embodiment is specially suited is that of assembling several laminae comprising an article such as a Christmas tree star, rosette, or other decorative'holder, shade, frame or reflector for a small electric light or candle. It will be readily understood that the structure shown in the drawing is useful for many other purposes, and that the number, spacing and pattern of the punching and clenching stations may be widely varied without departing from the scope of the invention.

In the embodiment illustrated, the two die assemblies comprise an upper assembly designated, in its entirety, iii, arranged to reciprocate in cooperation with a lower assembly designated, also in its entirety, i i. The dies may be mounted for vertical operation in any suitable press. Here the work to be done is to punch and clench together a plurality of sheets at five stations surrounding registered perforations in all sheets; and for this reason a centering post 12 is provided on the top of the lower assembly to iacili- 1 tate the proper positioning of the sheets thereupon for the punching and clenching operation. Such centering post thus serves similarly as any gage which might be required properly to align work in a press.

Fig. 1 is an elevational view of the two die assemblies. In solid lines the assemblies are seen in normal or inoperative position; in dotted lines two operational stages are indicated.

The upper assembly H3 is fixed to the hammer l3 of a suitable press. A portion only of the hammer I3 is seen; and no other part or" the press itself is shown. The lower asembly H is provided on the bottom with a central boss M by means of which the assembly may be mounted on, for instance, a perforated or countersunk block suitably attached to the bed of the press, so that the two assemblies are coaxial, as shown.

The two die assemblies are each of circular cross section. The upper surface of the lower assembly is seen in plan in Fig. 2; the bottom of this assembly is seen in plan in Fig. 3. The dies here shown are arranged to punch and clench at five equally spaced stations surrounding registered circular perforations to be placed concentrically with the dies, an axial section of the two assemblies on the plane being indicated by the line 99 of Fig. 3. Fig. 9 gives only a phantom view of the pairs of cooperating punching and clenching members of the two assemblies. Each pair of the five cooperating punching and clenching members of the two assemblies is of common design, and one pair of such members is shown in axial section at one operational stage in Fig. 8, which is fragmentary and much enlarged. The plane of the section of Fig. 8 is identified by line BB of Fig. 2. The fragmentary section of Fig. 10, showing an operational stage, relates to the plane of the section of Fig. 9, and the enlarged fragmentary section of Fig. 13 relates to the plane of the section of Fig. 8.

The work to be performed by these specific die assemblies is illustrated in Figs. 4, 5, 6 and 7. It is assumed that three sheets l5, l6 and H of fairly soft material, forming the laminae of an article such as a Christmas tree rosette, or the like, each sheet having a central circular perforation of common diameter, are desired to be clenched together at five stations surroimding the registered perforations.

Figs. 4 and 5 are fragmentary top plan views of the pile of sheets, the sheet being torn away on two edges to show that there are three in the pile. In each figure the centering post I2 is seen, the same passing through the registered perforations of the three sheets. Fig. 4 shows five circular holes l8, punched through the three sheets, the holes being alike and being spaced at approximate intervals of 72 around the registered perforations of the three sheets.

The punching of these holes is the first operation of the present embodiment of the invention. Each hole is formed by a descending punch of circular cross section having a point formed in the present embodiment of three equally spaced bevels so that no dropping of the material of the sheets occurs, but instead the material is torn and flared as a plurality of burrs IS on the underside of the pile, such as shown in perspective in the enlarged fragmentary view of Fig. 6. A succeeding operation of the embodiment here illustrated flattens these burrs against the underside of the bottom sheet of the pile, as shown in Fig. 7, simultaneously preventing the burrs from spreading so as to cover the hole. Thus, five sets of rough flanges 2B are formed of the burrs surrounding the five holes on the underside of the bottom sheet, whereby the material of the upper and middle sheets, forced through the bottom sheet in the punching operation, becomes, in essence, a plurality of hollow rivets securing the three sheets together.

The holes l8 are formed by means of five like punches 21, 22, 23, 24, 25, rigidly fixed to a disk 25 through which a plunger 21 is driven. See Fig. 12, which shows the structure in elevation and separate from the upper die assembly. This structure is also seen in axial section in Figs. 9 and 10. The structure is slidably mounted withs in a cylindrical head 28, the upper portion of which is axially counterbored down to a shoulder 29 at a diameter slightly greater than that of the disk 25, and thereafter to a floor at 30. It will be noted from Fig. 12 that the upper part of each punch is provided with a portion of increased diameter for the purpose of reinforcing the same. The lower portions of the five punches are received in five spaced bores 31 in the bottom portion of the head 28. See Fig. 11, which is a bottom plan view of the upper die assembly; compare, also, Figs. 9 and 10.

The head 28 is threaded onto a cylindrical die base 32 at 33. The base 32 is provided with a centerbore of stepped diameters, the greatest being at the upper portion. From the top of the centerbore down to a shoulder at 34 constitutes the lower end of the hammer l3 of a suitable press. The base 32 is secured to the hammer 13 by means of a set screw 35.

The upper portion shank 21 is slidably received in the lower portion of the centerbore of base 32,

as shown; and surrounding the shank and en gaging the lower surface of the base 32 and the upper surface of the disk 26 is a compression spring 35 which normally operates to maintain the five punches in the relative position illustrated in Figs. 1, 3 and 9, that is, beyond the bottom surface of the head 23 and in operative position to engage the work.

The lower die assembly comprises a cylindrical base 3'! upon which is mounted a head 38, the latter arranged to reciprocate vertically. The bottom of the lower die assembly is seen in Fig. 3. The boss 14, mentioned above, by means of which the lower die assembly may be secured to the bed of a press, is integral with the base 3? (see Figs. 3 and 9). With reference to Fig. 9, the head 33 is seen to be axially counterbored from the bottom so that the head forms a shell partly fitted over the cylindrical base 32'. Dotted lines in Fig. 9 indicate the lowermost position attained by the head 33 in its vertical movement.

The axial countcrbore of head 38 is initially of such diameter as to leave but a relatively thin wall at the lower portion of the head; the d1- ameter of the axial counterbore is next stepped,

down forming a considerable shoulder 38, and thereafter continued upwardly in the head 38, ending at a surface 3911. Around the smaller and upper portion of the axial counterbore of the head 38 the shoulder 39 is counterbored parallel to the axis of the head at four stations spaced at 90 intervals, to provide four like counterbores 40, 46 (see Fig. 3; an opposing pair of the counterbores 40, 48 are seen in axial section in Fig. 9). Each counterbore 48 is stepped down in diameter forming a shoulder 4|, and the upper portion 42 of the counterbore is tapped (see Fig. 9; to simplify the figure, the threads of the portions 42 v are not shown).

The base 3'! is provided with four like bores 43, 43, parallel to the axis of the base and spaced to align with the counterbores 4-8, 46, of the head.

Each bore 43 is stepped in diameter forming a' lower portion 44 of greater diameter, a shoulder 45, and an upper portion 46 of lesser diameter.

Like bolts 41, 48, 49 and 56 serve to securethe head 38 to the base 3']. Each bolt is passed through the upper portion 46 of a bore 43 and is screwed into the upper portion 42 of a counterbore 40, the upper end only of each bolt being threaded. Surrounding each bolt between 'por.- tions 46 and 42 is a compression spring 5| under tension. (See Fig. 9, partly shown.) On the top of the base 3! is a central boss 52, as seen in Fig. 9, the diameter of the boss being substantially that of the upper portion of the axial counterbore of the head 38 so that the boss cannot interfere with vertical movement of the head 38. The upper surface of the base 31 surrounding the boss 52 and forming a shoulder is designated 53. Each compression spring 5| bears against the opposing shoulders 4| and 53. The lengthTof each bolt is such that the springs 51 may raise the head 38 with respect to the base 3'! to the position shown in solid lines in Fig. 9 before the heads of the bolts 41, 48, 49 and 58 engage the shoulders 45 and so limit further movement. It will be readily seen in Fig. 9 that the head 38 may be depressed until shoulder 39 strikes shoulder 53. Normally, however, in ordinary under surface of the disk 58 is a relatively powerful compression spring 60 under tension; and held so by means of a circular nut 6i screwed onto the threaded part (at 5'!) of post 56 and into a central countersink of the disk 58. The nutv 6! prevents expansion of the spring 68 and consequent elevation of the disk 58; but the disk 58 may, under downwardly applied pressure, further compress the spring and move downwardly with respect to the post 56. Thus the disk 58, ,while normally held in the position shown in Fig. 9 by a spring capable of considerably resisting downward movement of the disk, the disk is not rigidly mounted.

The upper part of the head 38 is provided with five bores 62 spaced around the center of the head at intervals of 72, and in mounting the die assemblies in a press the two assemblies are so mounted that the axes of the bores 62 are registered with the axes of the five bores 3| of the head 28 of the upper die assembly. Within each bore 62 is received the upper part of one of five posts 63, 64, 65, 66 and 51 rigidly mounted on disk 58, as by driving the several posts into spaced bores through said disk. 'The upper end of each post is stepped down in diameter to form a shoulder 68 and a coaxial nipple 69 as most clearly shown (in axial section) and on enlarged scale in Figs. 8 and 13. See, also, Fig. 2, which is an upper plan view of the lower die assembly, and shows the spaced bores 62 with the nipples 69 and shoulders 68 of the five posts. Normally,

the upper extremity of each nipple 69 is retracted operation, these shoulders never come into contact as a slighter downward movement of head 38 is ample for the purposes of the apparatus.

The post l2 mounted on the top of head 38 of the lower die assembly for the purpose of registering the perforations of sheets desired to be punched and clenched together is, in the present embodiment, shown as a cap screw, "the head of which is conical, so that perforated sheets placed thereupon are caused to drop into registered position as shown in Fig. 9. Post I2 is screwed into a threaded portion 54 of a center-- bore through the head 38. The lower portion 55 of the centerbore is of reduced diameter, and is equal to the diameter of an axial bore through post [2. Rigidly mounted on the boss 52 of the base 37 is a vertical post 56, the upper portion of 'which is of lesser diameter and freely passes through the lower portion 55 of the above mentioned centerbore and the axial bore of post I2. Approximately midway the length of post 56, the diameter is stepped, and the upper part of the lower portion of greater diameter 56 of, the post is threaded at 51. The post 56 passes freely through a disk 58 of diameter slightly less than that of the upper portion of the axial counterbore of the head 38, within which said'disk is between the upper surface 59 of boss 52 and the within a bore 82 as shown in Fig. 9, as shown,

. sufficiently so that if the two die assemblies are brought together to efiect contact between the under surface of the head 28 and the upper surface of the head 38, the punches 2|, 22, 23, 24 and 25 may be accommodated by the upper portions of the five bores 62. See Fig. 2.

The post '56 normally extends through and beyond the post l2 as shown in Figs. 1 and 9. The upperend of the post 56 is designated 70. The lower part of the head 28 of the upper die assembly is axially bored at H (see Figs. 9 and 10) to accommodate the post l2 when the two die assemblies are brought together. The bore continues through the head at reduced diameter at T2, the portion 12 of the bore being of suificient diameter to permit passage therethrough of the upper portion of post 56 when the die assemblies are brought together. See Fig. 10. The shank 21 of the punch assembly (see Fig. 12; also Figs. 9 and 10) is continued through the disk 28 and extends downwardly beyond said disk.

I The operation of the apparatus will be readily understood. Let it be assumed that the two die assemblies are so positioned in a press that the punches 2|, 22, 23, 24, and 25 are respectively coaxial with the posts 63, 54, 65, 6E, and 61, as shown in the drawing. A plurality of sheets of material desired to be clenched together at five stations of position surrounding registered circular perforations in the several sheets are first placed, in superposed arrangement, over the post' on the upper surface of the head 38 so that the registered perforations of the sheets are roughly coaxial with said post, and then allowed to drop onto the head 38, the conical shape of post l2 serving to center the sheets as they descend. The sheets come to rest upon the upper surface. of the head 38 as indicated in Fig. 9. In the drawing, where three such sheets are shown, the lowermost is designated 11,. the middle one l6, andthe uppermost l5.

The first portion of the cyclic operation of the hammer 13 of the press serves to bring the upper die assembly down against the lower assembly, and the five punches El, 22, 23, 24, and 25 against and through the superposed sheets l5, l6, and H, the sharpened ends of the five punches entering the upper portions of the five bores 62. The transfixing action of the plungers is common. Fig, 8, which is an axial section (of. line 88, Fig. 2) through plunger 25 and that bore 62 which accommodates post 61, is clearly illustrative. Here, in Fig. 8, the sharpened point of the plunger 25 is seen to have passed through the three superposed sheets l5, I6, and Il, and the lower surface of the head 28 of the upper die assembly has contacted the upper surface of the sheet I5, pressing all sheets against each other and the sheet H against the upper surface of the head 38. The sharpened point of the plunger 25 is seen received within bore 62, and the nipple 69 of post 57 is seen to be amply retracted so as not to contact the point of the plunger. Note, here, that burrs is have been forced downwardly into bore 82, and that tongued portions of sheets l and it have been carried through the rupture of sheet Ii.

As the cyclic operation of the hammer l3 continues the head 38 and the superposed sheets are carried downward together, the shoulders 4|, 4! compressing the springs 5i 5| against the shoulder 53 of the base 37. Dotted lines in the lower portion of Fig. 9 indicate normal extreme positions attained by head 38 and the bolts 41, 48, 49, and 5t (41 and 49 only being visible in the figure). As the head 38 descends the disk 58 remains stationary, of course, with the result that the bores 62 receive more and more of the five posts 83, 64, B5, 66, and El. However, the post 5? remains stationary at all times, and before the points of the punches meet the nipples 69 of the five posts the top 78 of post 5'! passes through the bore at 72, due to the relative movements of parts, and the top '18 is struck by the lower end of the shank 27 forcing the shank and its related disk 26 remain stationary during the remainder of the descent of the upper die assembly. This operates, of course, to arrest the descent of the five punches, to withdraw, in effect, the punches from the holes l8 (of. Fig. 4) previously made in the superposed sheets and to cause them to assume retracted positions in the bores 31, 3|. See Fig. 10, where the disk 25 with its five punches is shown raised relative to the upper die assembly, as a whole, the compression spring 36 being considerably compressed between the disk and the base 32. In the continuing operation the superposed sheets are brought down until presently the holes I8 receive the nipples 69, and the tongued portions of the sheets strike the shoulders 58 of the posts 63, 64, 65, 66, and 67 and flare out on said shoulders to form rough flanges 20 as shown in Figs. 5 and '7. Fig. 13, another axial section on line B-8 of Fig. 2, illustrates in detail the relative positions of parts at the normal extreme downward station of the upper die assembly. Note here that the nipple 69 of post Bl is received not only through hole l8 but also within the lower portion of bore 3i (plunger 25 being retracted therein), and that the burrs.

is have been flattened between the shoulder 68 and the sheets themselves, the area surrounding normal operating conditions resistance to descent of disk 58 sufiicient toprevent the shoulders 68 from receding during the clenching action; but is provided for the purpose of allowing the disk to descend under extreme conditions, as, for example, where more sheets than that number for which the die assemblies are set accidentally on head 38.

I claim:

1. Apparatus for piercing and clenching superposed sheets which comprises a vertically reciprocatin hammer and a stationary bed, said hammer having a chamber therein and an angularly spaced series of perforations extending vertically from said chamber to the bottom of said hammer; a spring loaded member mounted within said chamber for vertical movement relative to said hammer, said member having mounted thereon an angularly spaced series of downwardly directed punches normally extending through said perforations and beyond the bottom of said hammer; another spring loaded member mounted on said bed for vertical movement relative thereto, said ot er member having mounted thereon an angularly spaced series of anvils each thereof being aligned with one of said punches; a spring loaded platform mounted on said bed for vertical movement relative thereto, said platform having an angularly spaced series of perforations each thereof aligned with one of said anvils; and a detent mounted on said bed and extending freely through said platform for arrestin downward movement of said first named member and said punches at a particular station of position of said hammer.

2. Apparatus for piercing and clenching a pile of superposed centrally perforate sheets around the central perforations thereof which comprises a reciprocating hammer anda stationary bed, said hammer having a chamber therein and a plurality of perforations extending from said chamber to the bottom of said hammer, one of said last named perforations being centrally disposed with respect to the others thereof and the said others being angularly spaced around it;'

mounted on said bed for vertical movement relative thereto, and having an angularly spaced series of perforations each thereof being aligned with one of said punches and one of said anvils; and a detent centrally mounted on said bed and extending upward freely through said other member and through said platform, said detent arresting downward movement of said first named member and said punches at a particular station of position of said hammer; and a centering gage mounted on said detent above said platform for centering the sheets of said pile.

3. Clenching attachment for a press having a vertically reciprocating hammer cooperating with a stationary bed therebeneath which comprises a member resiliently mounted on said hammer for vertical movement relative thereto, said member having mounted thereon an angularly spaced series of punches; another member resiliently mounted on said bed for vertical movement relative thereto, said other member having mounted thereon an angularly spaced series of anvils each thereof being aligned with one of said punches; a platform resiliently mounted on said bed for vertical movement relative thereto, said platform having an angularly spaced series of perforations each thereof being aligned with one of said punches and one of said anvils; and a detent mounted on said bed for arresting the firstnamed member at a particular station of position of said hammer during descent thereof.

JOSEPH PETTOROSSI.

REFERENCES CITED The'following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 818,221 Thompson May 19, 1885 689,394 Gregory Dec. 24, 1901 1,201,539 Arey Oct. 17, 1916 1,286,210 Bengler Dec. 3, 1918 2,333,966 Weiss Nov. 9, 1943 2,404,197 Sirp July 16, 1946 2,430,377 Vorreyer Nov. 4, 1947 FOREIGN PATENTS Number Country Date 39,842 Austria Nov. 25, 1909 

